US3516449A - Fringe forming mechanism for looms - Google Patents

Description

June 23, 1970 Q DARVWN ET AL FRINGE FORMING MECHANISM FOR LOOMS 5 Sheets-Sheet 1 Filed Aug. 2'7, 1968 INVENTORS HOWARD u. NELSON GLIIFFORD DARWIN WWW- ATTORNEY June 23, 1970 c. DARWIN ET AL FRINGE FORMING MECHANISM FOR LOOMS 5 ShcotsShcet 3 Filed Aug. 2'7, 1968 INVENTORS HOWARD I. NELSON CLIFFORD DARWIN ATTORNEY June 23, 1970 c. DARWIN ET AL FRINGE FORMING MECHANISM FOR LOOMS 5 Sheets-Sheet '6 Filed Aug. 2'7, 1968 ENVENTORS HOWARD B. NELSON GHFFORD DARWHN ATTORNEY June 23, 1970 c. DARWIN ET AL 3,516,449

FRINGE FORMING MECHANISM FOR LOOMS Filed Aug. 27, 1968 5 Sheets-Sheet 4 I46 @y/ID Fl G. 7 5:

I III IIHI H INVENTORS HOWARD l. NELSON CLIFFORD DARWIN ATTORNEY June 23, 1970 c. DARWIN ET AL FRINGE FORMING MECHANISM FOR LOOMS 5 Sheets-Sheet 1) Filed Aug. 27, 1968 FIG.9

PROTECTION STOP WEFT

STOP

WARP

STOP

INVENTORS NN I m LA VI E N N a QR R w AW M WL 00 H United States Patent US. Cl. 139-24 11 Claims ABSTRACT OF THE DISCLOSURE A fringe forming mechanism for looms operating with a positive type warp let-off in which the output and input of the let-off is disconnected during the formation of fringe. The fringe is formed by engaging a normally inactive auxiliary cloth take-up which when engaged, takes up cloth at a faster than normal rate.

BACKGROUND OF THE INVENTION This invention relates to looms and more particularly to an improved fringe forming mechanism wherein the cloth being woven is periodically taken up at greater than normal speed and the warp is allowed to be drawn freely from the warp beam. The present fringe forming mechanism is particularly useful in the manufacture of terry towels having fringes on opposite ends thereof.

A number of prior art mechanisms have been used to produce a fringe by providing auxiliary cloth takeup means which take up the cloth at a higher than normal speed and at the same time release a brake on the warp beam to allow the warp to be drawn off at a faster than normal rate.

Most modern looms operate with a positive warp letoff mechanism whose variable speed output component is geared to the warp beams. A typical let-off of this type is shown in Hunts US. Pat. No. 2,786,491, dated Mar. 26, 1957. US. Pat. No. 3,366,146 to G. A. Williams represents one way of producing a fringe on a loom operating with a positive let-off. In this patent, there are shown means to disconnect the output end of the positive let-off. By disconnecting the output of the positive let-off, the warp beam can be pulled ahead to allow fringe weaving. Positive let-off such as that shown in the above Hunt patent have a variable transmission means between the input and output drive positions of the let-off. This variable transmission means assumes different settings in response to the tension of the warp. When the output of the let-off is disconnected, the variable transmission portion of the let-off will change its setting in an attempt to compensate for the changes in warp tension. When the fringe section is finished and the out-put portion of the let-off is re-connected, the setting of the variable transmission means is considerably off from its normal setting. While trying to adjust to the correct setting, the variable transmission means will fluctuate between high and low settings until it finally zeroes in on the proper setting. During this period of adjustment, there will be a great deal of variation in the density of the cloth produced, thus lowering the quality thereof.

SUMMARY OF THE INVENTION The present invention solves the above problems and has for its principal object, the provision of means to disconnect the input and output portions of a positive let-off. This effectively freezes the variable transmis siton portion of the positive let-off in its correct setting.

Another object of the invention is the provision of means for disconnecting the output portion of a positive let-off operating on a multiple shuttlebox loom wherein ice disconnection will correspond to the position of the shuttle boxes and which can be adjusted to correspond to any one of several different shuttle box positions as desired.

A further object of the invention is the provision of novel auxiliary take-up means.

BRIEF DESCRIPTION OF THE DRAWINGS Other objects and advantages will become apparent from the following detailed description together with the accompanying drawings in which:

FIG. 1 is a schematic perspective view of a multiple box terry loom equipped with the present invention;

FIG. 2 is a rear elevation of clutch means for disconnecting the output portion of the positive let-off, portions being in section;

FIG. 3 is a transverse section of the preferred form of auxiliary take-up mechanism;

FIG. 4 is a plan view of the preferred form of auxiliary take-up mechanism, portions being in section;

FIG. 5 is an end view of a first modification of the auxiliary take-up mechanism;

FIG. 6 is a longitudinal section of a second modification of the auxiliary take-up mechanism;

FIG. 7 is an end view of the positive let-01f;

FIG. 8 is a longitudinal section of clutch means for disengaging the input portion of the positive let-off;

FIG. 9 is a diagrammatic view of means for disengaging the clutch of FIG. 2;

FIG. 10 is a fragmentary rear elevation looking in the direction of arrow 10, FIG. 9; and

FIG. 11 is a diagrammatic view of electric circuits used in connection with the invention.

GENERAL DESCRIPTION Referring specifically to FIG. 1 of the drawing, the fringe forming mechanism of the present invention is shown in association with a terry loom having the usual lay 12 which supports at one end thereof a plurality of shiftable shuttle boxes 14-17. The shuttle boxes 14-17 are shifted by the usual box-motion, generally designated by the reference character 18. The box-motion is in turn controlled from the usual pattern mechanism 20 such as a paper indicated dobby of the type shown in US. Pat. No. 2,856,966, Nov. 2, 1968 to Thevenon. A pair of box- motion rods 21 and 23 normally depend from separate dobby jacks or the like and are attached to sliding teeth associated with pinion gears which form part of the box-motion. The operation of the sliding teeth on this type of box motion is shown very clearly in US. Pat. No. 1,668,146 to A. A. Gordon issued May 1, 1968. Rods 21 and 23 are equivalent to rods 62 and 61 respectively in Gordon.

A warp beam 22 supplies the ground warp W and a terry warp beam 24 supplies the terry warp. The ground and terry warps are led through a reed 26 on the lay to the cloth C. The cloth is taken up by take-up mechanism generally indicated at 28 and includes a takeup roll 30. The take-up mechanism can be of any type as shown for example in US. Pat. No. 1,872,933 to W. E. Lundgren.

The auxiliary take-up mechanism of the present invention generally indicated at 32 is inactive during normal weaving and is activated during fringe formation in a manner to be descrbed.

A positive let-off mechanism, generally indicated at 34 is employed to operate the warp beam 22 so that ground warp W may be released at a uniform rate and under uniform tension during normal weaving. Let-off 34 is of the type shown in the above mentioned Hunt patent.

3 DESCRIPTION OF THE LET-OFF Referring to FIGS. 1, 7 and 8, the positive let-off 34 is of the previously mentioned Hunt type which has an input shaft 36 driven from the loom, and an output shaft 38 drivingly connected to the warp beam 22 through appropriate gearing, not shown. The input shaft 36 drives the output shaft 38 through a variable drive mechanism commonly known as a reeves pulley arrangement, generally indicated at 40. This type of pulley arrangement includes a pulley 42 on the input shaft which is drivingly connected to a pulley 44 on the output shaft 38 through a drive belt 46. The effective diameters of the pulleys are automatically adjusted by mechanism, not shown, which is responsive to the warp tension. In this way, the warp beam will be driven so that a constant linear velocity of warp is let-off under uniform tension.

Located on the input shaft 36, is a first clutch 48, see FIGS. 7 and 8, which is normally engaged. Clutch 48 has an element 50 which is slidingly keyed to shaft 36 by a key 52 and an element 54 which is loosely mounted on shaft 36. A spring 56 maintains element 50 in engagement with element 54. A worm gear 58 is integral with element 54 and is driven by a worm 60 which is in turn driven from the loom by a chain and sprocket drive, generally indicated at 62. As long as elements 50 and 54 are engaged, the pulleys 42 and 44 will be driven from the loom.

A lever 64 pivoted at 66 has a depending arm 68 which bears against clutch element 50. A rod 70 is attached to lever 64 at 72 and is operated from the pattern mechanism through linkage means generally indicated at 73, see FIG. 1. Upward motion of rod 70 as shown in FIG. 7, operates lever 64 so that depending portion 66 pushes against an annular flange 78 on clutch element 50. When lever 64 is operated in this manner, clutch element 50 will slide to the right in FIG. 8 against spring 56 and will become disengaged from clutch element 54. When elements 54 and 50 are disengaged, pulleys 42 and 44 will no longer be driven.

Referring to FIG. 2, there is shown a second clutch 80 which is normally engaged and maintains output shaft 38 in driving relation with the warp beam 22. Clutch 80 is mounted on a shaft 82 which is drivingly connected to warp beam 22. Clutch 80 may be on any commercial type of clutch such as an automotive clutch. As shown in FIG. 2, clutch 80 indicates a housing 81, a driven clutch disc :83 slidingly keyed to shaft 82 at 84 and a driving clutch element 86 fixed to a sleeve 88 which is in turn fixed to a worm. gear 90. Elements 82 and 86 are enclosed in housing 81 and the assembly of elements 86, 88 and 90 is freely rotatable on shaft 82. Worm gear 90 is rotated by a worm 92 which is fixed to output shaft 38. As long as pulley 44 is rotated, clutch disc 86 will be rotated. Compression springs 94 acting through extending members 96 maintain clutch disc 83 in engagement with disc 86. Bearings 98 are interposed between disc 83 and extensions 96 to allow clutch disc 83 to rotate relative to members 96. An operating lever 100 pivoted at 102 to a stationary supporting member 104 is pivotally connected to a sleeve 108 which is slidable in shaft 82. Located within housing 81 are levers 110 pivoted at 112 to supporting members 114. The inner ends of levers 110 adjacent shaft 82 bear against a portion 116 of sleeve 108 which extends into the housing 81. The outer ends of levers 110 bears against springs 94. Clockwise rotation of lever 100 will cause hub 108 to slide to the left in FIG. 2 and cause levers 110 to swing clockwise. The clockwise movement of levers 110 will depress springs 94 and pull clutch element 83 away from engagement with clutch element 86. Clutch 80 is shown in its disengaged position in FIG. 2.

LET-OFF DISENGAGING MECHANISM The mechanism to operate lever 100 to disengage clutch 80 is illustrated in FIGS. 1, 2, 7, 9 and 10. Re-

ferring particularly to FIGS. 1 and 9, the previously mentioned box-motion 18 comprises a pair of cranks 118 and 120. Each crank is selectively rotated by a pinion gear, not shown, so that it will occupy either an upper or a lower position. The pinions are controlled by sliding teeth which are in turn controlled from the pattern mechanism through rods 21 and 23 as previously mentioned. Cranks 118 and 120 operate to either selectively lift or lower connecting links 122 and 124 respectively. Link 124 is pivotally attached to a first box lever 126 which is pivoted at 128 to a fixed part of the loom. Link 122 is pivotally attached at 129 to a second box lever 130 which is pivoted to the first box lever at 132.

Lever 130 is operatively connected to shuttle boxes 14-17 through linkage illustrated diagrammatically at 134 in FIG. 9. Since cranks 118 and 120 can each selectively place their respective links 122 and 124 in either of two positions, lever 130 will be capable of being moved to four different positions. Each position that lever 130 occupies will act to place a different shuttle box in active position. In FIG. 9, lever 130 is in the position which places the first shuttle box 14 in active position. The sequence of shuttle box positions is illustrated in US. patent to C. P. Bergstrom No. 3,128,796 issued Apr. 14, 1964. A cross link 136 is pivotally connected at 138 and 140 to links 122 and 124 respectively. A center line drawn between pivots 138 and 140 will occupy four different positions depending on the positions of the shuttle boxes. The four positions of links 136 are represented by dotted center lines A, B, C and D which correspond to active positions of shuttle boxes 14-17 respectively.

A lever 142 pivotally mounted on a shaft 143 has a pair of arms 144 and 146. A connecting rod 148 is pivotally connected at 149 to cross link 136 and at 150 to arm 144 of lever 142. Pivot 149 is placed advantageously between pivots 138 and 140 so that it will be capable of occupying four different positions, depending on which of the positions A, B, C, or D of link 136. Arm 144 can therefore be swung to four different positions and cause arm 146 to swing four corresponding positions as indicated by A, B, C and D which correspond to positions A, B, C and D respectively of link 136. A connector 152 is pivotally attached at 154 to arm 146 and to a slide member 155 at 156. Member 155 is slidable in a block 158 mounted on the 100m frame and has a cam surface 160 which extends beyond block 158, see FIG. 10.

Cam surface 160 has a high portion 162 and sloping portions 164 on either side thereof. A follower 166 is slidingly mounted in a fixed sleeve 168 and bears against cam surface 160 at one end and against the upper portion of lever 100 at its other end, see FIG. 2. Since arm 146 will occupy one of four positions which correspond to the four shuttle box positions, high portion 162 of cam surface 160 will engage follower 166 for one box position only. As shown in FIG. 4, the first box position (shuttle box 14 active) corresponds to the position of block 155 wherein follower 166 is so engaged with high portion 162, lever 100 is rocked clockwise as shown in FIG. 2 wherein clutch 80 is disengaged as previously described. When the shuttle boxes 15, 16 and 17 are in active position, follower 166 will be engaged with portion 164 of cam surface 160 and clutch 80 will be engaged. Lever 152 is adjustable so that follower 166 will engage the high portion of cam 160 to correspond to the active position of any of the shuttle boxes 14-17. A series of holes 1A, 1B, 1C and 1D in lever 152, allow the slide member 155 to be adjusted so that the placing of any of the shuttle boxes will coincide with the engagement of high portion 162 with follower 166. Positions A, B, C and D correspond to holes 1A, 1B, 1C and 1D respectively. The indicated positions of lever arm 146 and the corresponding holes in connector 152 coincide when block 155 is in the clutch disengaging position as shown in FIG. 9. When the shuttle box which is selected to coincide with fringe formation is in active position, pivot 154 will be placed in whichever of the holes 1A, 1B, 1C and 1D is aligned with arm 146 while block 155 is in clutch disengaging position.

When the pattern calls for fringe formation, the let-01f 40 will be operatively disconnected from the warp beam through the disengagement of clutch 80 and the let-01f will be rendered non-responsive to changes in warp tension by disengagement of clutch 48. Since clutches 48 and 80 are both controlled from the pattern and can be adjusted to disengage at the same time, the let-off will be effectively frozen so that the pulleys 42 and 44 will maintain their setting which they had before fringing. When the fringe is formed and normal weaving resumes, the proper setting of the pulleys will not have been disturbed and the letoff will operate to let-off warp yarn at the same uniform rate and tension as it did before fringing.

AUXILIARY TAKE-UP MECHANISM Referring to FIGS. 1, 3 and 4 there is illustrated a preferred embodiment of the previously mentioned auxiliary take-up mechanism 32. This mechanism comprises a differential gear assembly having an input gear 170, mounted on a second input shaft 171 an out-put gear 172 mounted on a second output shaft 173 and planetary gears 174 rotatably mounted on stub shafts 176 which are supported in a ring 178. Planetary gears 174' are engaged with said input and output gears. The input gear is driven from a constantly rotating shaft 180 commonly referred to as the bottom shaft through gearing generally indicated at 182. The output gear 172 is drivingly connected to the take-up roll 30 through appropriate gearing generally indicated at 184 and including a sprocket gear 185 fixed to shaft 173. Gear 170 normally drives planetary gears 174 so that they revolve with ring 178 around gears 170 and 172 with the result that gear 172 remains stationary. A brake band 186 is trained around the ring 178 and is effective when tightened to prevent ring 178 and gears 174 from orbiting about gears 170 and 172. When this happens, gear 170 will drive gear 172 through planetary gears 174. Gear 172 will in turn drive the take-up roll 30. The mechanism for applying the brake band 186 is mounted on the usual color shaft 188 and is generally indicated at 190. Color shaft 188 is journaled in the loom frame and extends across the lower portion of the loom. A color indicator lever 192 is part of the box motion 18 and is moved rearwardly and forwardly in synchronism with and in direct proportional relationship with the vertical movements of the shuttle boxes 1417. A link 194 connects the lower portion of color indicating lever 192 to a crank 196 fixed on one end of color shaft 188. The other end of shaft 188 also has a crank 197 thereon which is connected, by means of a link 198, to bell crank lever 200 pivoted at 202 to the usual multi-color stationary magazine 204.

Magazine 204' may be of any well known type having a plurality of vertically extending channels therein, each of which is adapted to contain a supply of bobbins. Magazine 204 includes a forwardly and rearwardly extending bobbin or channel selector shaft 206 which is shifted forwardly by its connection to bell crank 200 so to position the same in different positions corresponding to the different angular positions occupied by the color shaft 188 and thus corresponding to the different positions occupied by the shuttle boxes 14-17. Magazine 204 may be a type such as is disclosed in US. Patents to Ryan and Hoffman Nos. 1,030,748 and 1,521,182 respectively. As disclosed in Ryan, each time bobbin selector shaft 206 is moved from one position to another, bobbins may be transferred from a different one of the channels of magazine 204 when called for by the usual filling replenishing mechanism, not shown. There is a channel which corresponds to each shuttle and the position of selector shaft 206 will be adjacent the channel which corresponds to the shuttle which is in active position. Referring particularly to FIG. 3, one end of brake band 186 is anchored to shaft 188 at 207 gage follower 212 when a selected and the band itself is trained around ring 178 so that the other end of the band is attached to one end of a lever 208 at 209.

Lever 208 is pivoted on a support rod 210, see FIG. 1. The other end of lever 208 has a follower 212 which is engaged by a cam 214. A spring 216 holds follower in engagement with cam 214. Cam 214 has a constant radius with the exception of high portion 218 and is secured to shaft 188 by a screw 220 which is threaded through a hub 222 of cam 214. When the high portion 218 engages follower 212, lever 208 is rocked counterclockwise and brake band 186 is tightened thus preventing ring 178 and planetary gears 174 from orbiting around gear and 172. The tightening of brake band 186 will cause gear 172 to be driven as previously described and the auxiliary take-up 32 will proceed to rotate cloth roll 30 at a faster rate than normal. Just as the clutches which control the let-off mechanism 40 can be adjusted to operate for any given shuttle box, cam 214 can also be adjusted. Since color shaft 188 is moved angularly in correspondence with the movement of the shuttle boxes, screw 220 can be loosened and cam 214 moved to a position in which high portion 218 will enshuttle box is in active position. Screw 220 is then tightened and cam 214 will operate the auxiliary fringe forming device 32 only when the same shuttle box which was selected is once more in active position.

FIRST MODIFIED AUXILIARY TAKE-UP MECHANISM Referring to FIG. 5, there is shown a first modification of an auxiliary take-up mechanism generally indicated at 224. This modification is similar to the arrangement shown in FIGS. 1, 3, and 4 except that the plurality of gears 174 are mounted within a ring 226 which has ratchet teeth 232 on its outer periphery. A hold pawl 228 pivoted at 230 is utilized to engage the teeth 232 of ring 226 and hold it against rotation when it is desired to engage the auxiliary take-up 224 for forming fringe. A spring 234 normally holds pawl 228 out of engagement with teeth 232. A rod 236 is attached to pawl 228 at one end and to lever 208 at its other end. Lever 208 is operated by cam 214 in the-same manner as shown in the preferred auxiliary take-up. When the high portion 218 of cam 214 engages follower 212, lever 208 is rocked counter-clockwise and rod pulls pawl 228 clockwise against spring 234 to engage teeth 232 of the ring.

SECOND MODIFIED AUXILIARY TAKE-UP MECHANISM Referring to FIG. 6, there is illustrated a second modification of an auxiliary takeup mechanism generally indicated at 238. This mechanism includes a clutch 240 having a first clutch element 242 keyed at 243 to a second input shaft 244 for rotation therewith. A second clutch element 246 is keyed at 247 to a second output shaft 248 which is in the form of a sleeve freely mounted on shaft 244. Sprocket gear is fixed to shaft 248 and is operatively connected to take-up roll 30 as part of gearing 184 as previously described. Clutch 240 is operated from a rod 250 which is pivotally connected at one end to one arm 252 of a bell crank lever 253 which is pivoted at 254 to a fixed part of the loom. The other arm of lever 253 is connected to a forked member 256 which straddles shaft 248 and bears against an annular projecting portion 258 of clutch element 246. Projecting portion 258 has an L shaped cross section. Cam 214 operates lever 208 in the same manner as previously described. When high portion 218 lifts follower 212, lever 208 is rocked so that rod 250 is lifted whereupon bell crank lever 253 is rocked counter-clockwise to push clutch element 246 into engagement with element 242. spring 216 acts on lever 208 as previously described to maintain clutch 240 disengaged except when the high 7 portion 218 of cam 214 contacts follower 212 of lever 208.

STOP MOTION CONTROL During the formation of fringe there is likely to be a momentary slackening of warp tension which could result in loom stoppage because of the warp stop motion. This stop motion can be of the type as shown for example in US. Pat. No. 2,436,023 to Sepavich et al. When the shuttle box which initiates fringe formation is brought to active position, a shuttle is not picked across the loom. The usual weft stop motion depends on a length of weft being laid across the loom and the shuttle protection stop motion depends on the presence of the shuttle at a certain spot on the lay at a particular time in the loom cycle to keep the loom operating. Since the shuttle is not picked, these two stop motions also would normally operate to stop the loom. A typical weft stop motion is shown in US. Pat. No. 2,962,056 to Paul at al. and typical shuttle protection stop motion is shown in US. Pat. No. 2,781,794 to Borderweick et al. For this reason, there is provided stop motion control means for preventing the weft, warp and protection stop motions from stopping the loom during fringe formation.

Referring to FIGS. 1 and 11, a stop motion control cam 259 having a high portion 260 is mounted on color shaft 188. Cam 259 is fixed to shaft 188 by a screw 261 which can be loosened to allow for adjustment of cam 259 relative to the shaft. Cam 259 controls a normally open switch 262 which forms part of the loom circuit diagrammatically illustrated in FIG. 11. This circuit comprises a pair of power lines 263 and 264 which supply current to the loom. Warp, weft and protection stop circuits are represented by the appropriately labeled boxes and are connected in series across power line 263 and 264 by a line 265.

A control relay 266 is connected in series with the above mentioned stop circuits so that relay 266 will be de-energized when any of these circuits are operated to break the connection to line 263. Relay 266 has to be maintained energized in order for the loom to continue running. Switch 262 forms part of a bridging circuit 267 across the stop circuits. When the high portion 260 of cam 259 engages the arm 268 of switch 262 so that it is thrown to the dotted line position in FIG. 11, circuit 267 will be closed and control relay 266 will remain energized and the loom will continue to run during fringing.

Cam 259 can be adjusted so that high portion 260 will close switch 262 when a particular shuttle box is placed in active position. The adjustment of cam 259 insures that the selected shuttle position will be the same one which precipitates fringe formation as previously described.

GENERAL OPERATION During normal weaving the positive let-off 34 is constantly operating to let-off warp W from beam 22 and the usual take-up mechanism 28 operates to take-up a small predetermined amount of cloth each pick. The taking-up of the cloth creates a tension on the warp which regulates the pulley drive setting on the let-off as previously described. When let-off 34 is thus operating to control the amount of warp being let off from beam 22, clutches 36 and 80 are engaged as previously described. During this period of normal weaving, the auxiliary takeup mechanism is disengaged and the box motion 18 operates to shift boxes 1417 in accordance with a selected color pattern. As an example, assume that boxes 15, 16 and 17 are being used for normal weaving. Each shift of the boxes by the box motion will cause color shaft 188 to operate bell-crank lever 200 and channel selector shaft 206 in accordance with the box motion. Bobbins will be selected from the three channels which correspond to boxes 15, 16 and 17 as they are needed. The cam 214 will be set on color shaft 188 so that follower 212 will be engaged with the low portions of the cam for each position which corresponds to the position of boxes 15, 16 and 17. Rod will be connected so that clutch 48 will not be disengaged during any of the positions of boxes 15, 16 and 17. Lever 142 will also be adjusted so that follower 166 will be engaged with sloping portion 164 of cam surface 160 so that clutch will remain engaged during the time boxes 15, 16 and 17 are in active position.

After a predetermined length of cloth is woven, the pattern mechanism will operate the box motion to shift the shuttle boxes so that box 14 is in active position to precipitate fringe formation. Color shaft 210 will rock cam 214 to the position shown in FIG. 3 so that the high portion 218 of cam 214 operates lever 208 to engage the auxiliary take-up mechanism 32. Rod 70 will be operated to disengage clutch 48 and lever 142 will assume the position shown in FIG. 9 thus bringing the high portion 162 of cam surface into engagement with follower 166 to disengage clutch 80. With the let-off thus disconnected at its input and output ends, it is effectively frozen so that the auxiliary take-up 32 can pull the warp W at an accelerated rate without interference from the let-off. Because it is frozen, the drive ratio settings of the pulleys 42 and 44 will not be disturbed. Since cam 259 is also fixed to shaft 188 it will be rocked so that high portion 260 operates switch arm 268 to close switch 262 to bridge the stop circuits. Control relay 266 will remain energized during fringe formation so that the loom will not be stopped by any of the previously described stop motions.

When a predetermined length of fringe is formed, the pattern mechanism will operate the box motion 18 to again shift the shuttle boxes to bring one of the boxes 15, 16 or 17 into active position and to resume normal weaving. When the shuttle boxes are so shifted, auxiliary take-up 32 will be disengaged and clutches 48 and 80 will be engaged. Let-off 34 will then begin to resume its function of letting off warp W in response to the warp tension produced by the normal take-up mechanism 28. The bridging circuit 267 will be disconnected and the warp, weft and protection stop motions will again be made operative.

Having described my invention, it will become obvious to one skilled in the art that other forms of clutches and coupling means could be used for the output and input ends of a positive let-off and for an auxiliary take-up without departing from the spirit of the invention although the preferred embodiments have proven to function satisfactorily. The true scope of the invention is encompassed in the following claim.

We claim:

1. In a loom having a warp beam; a cloth take-up mechanism including a take-up roll; a pattern mechanism; a positive let-off mechanism having an input shaft, and an output shaft operatively connected to said warp beam, said shafts being connected by a variable transmission means which transmits a variable drive from said input shaft to said output shaft in response to variations in tension in the warp being fed from said warp beam so as to maintain a substantially constant tension in said warp, a fringe forming mechanism comprising:

(a) let-off control means comprising:

( 1) means to operatively disconnect said output shaft from said warp beam, and

(2) means to render said transmission means substantially nonresponsive to variations in warp tension;

(b) normally inactive auxiliary drive means for driving said take-up roll at a substantially faster speed than that effected normally by said take-up mechanism; and

(c) actuating means responsive to said pattern mechanism to operate said let-off control means and to activate said auxiliary drive means.

2. The fringe forming mechanism as described in claim 1 wherein said let-off control means comprises:

(a) a first normally engaged clutch on said input shaft;

and

(b) a second normally engaged clutch operatively connecting said output shaft to said Warp beam; and

(c) means to disengage said first and second clutches upon operation of said actuating means.

3. The fringe forming mechanism as described in claim 1 wherein said auxiliary drive means comprises:

(a) a second driven input shaft;

(b) a second output shaft operatively connected to said take-up roll; and

(c) a normally disengaged coupling disposed between said second input shaft and said second output shaft for operatively connecting said shafts wherein said coupling is engaged to operatively connect said in put and output shafts when said control means activates said auxiliary drive means.

4. The fringe forming mechanism as described in claim 3 wherein said coupling comprises:

(a) a first clutch element mounted on said second input shaft for rotation therewith;

(b) a second clutch element mounted in driving relationship on said second output shaft for selective driving engagement with said first clutch element.

57 The fringe forming mechanism as described in claim 3 wherein said coupling comprises a differential gear assembly connecting said second input shaft to said second output shaft in normally non-driving relationship.

6. The fringe forming mechanism as described in claim 5 wherein said differential gear assembly comprises:

(a) an input gear mounted for rotation by said second input shaft;

(b) an output gear operatively connected to said second output shaft; and

(c) at least one planetary gear mounted in a support for orbiting about said input and output gears and for driving said output gear from said input gear when said planetary gear is prevented from orbiting about said input and output gears.

7. The fringe forming mechanism as described in claim 6 wherein said actuating means comprises:

(a) a brake ring for rotatably supporting said planetary gear;

(b) a normally inactive brake band mounted on said (e) a pivoted lever connected to said brake band for activating said band into a braking relationship with said brake ring;

(d) means under control of said pattern mechanism for operating said lever to activate said brake band.

8. The fringe forming mechanism as described in claim 6 wherein said actuating means comprises:

(a) a toothed wheel for rotatably mounting said planetary gear;

(b) a hold member for engaging said teeth and for holding said toothed wheel against rotation, said member being normally mounted in non-holding relationship with respect to said toothed wheel; and

(0) means under control of said pattern mechanism for bringing said hold member into holding relationship with said toothed wheel.

9. The fringe forming mechanism as described in claim 2 wherein said loom has multiple shuttle boxes and a box motion and wherein the means to disengage said second clutch comprises:

(a) a pair of shuttle box lifter levers which form part of said box motion, each of said levers being selectively movable to two different positions;

(b) an indicator lever pivoted to each of said box lifter levers so that it will be shifted to a different position upon each shuttle box shift; and

(c) linkage means connecting said indicator lever to said second clutch for disengaging same when said shuttle boxes are shifted and said indicator lever assumes one of several different positions.

10. The fringe forming mechanism as descried in claim 9 wherein said linkage means comprises:

(a) cam means movably mounted on said loom;

(b) a connecting rod operatively connecting said indicator lever to said cam means for moving said cam means; and

(c) follower means for translating motion from said cam to said second clutch to disengage said clutch.

11. The fringe forming mechanism as described in claim 10 wherein said cam means is a block slidably guided on said loom, said block having a high portion located between two inclined portions, said follower being arranged to disengage said second clutch when in engagement with said high portion and said rod being adjustable so that each of the several different positions of said indicator lever can be selected as the one position which will operate to disengage said second clutch.

References Cited UNITED STATES PATENTS 2,082,864 6/1937 Whitin 139-407 X 2,352,341 6/1944 Ott 13924 2,622,632 12/1952 Jarvis 139309 2,629,404 2/1953 Parker 13924 3,160,177 12/1964 Williams et al 139-24 3,347,280 10/1967 Burgess et al 13924 3,366,146 1/1968 Williams 13924 JAMES KEE CHI, Primary Examiner U.S. Cl. X.R. 139-99, 309

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